9 oz Nurser with medium flow silicone dome nipple. Sure Flow Vents: Less air and more liquid in baby's tummy. Mixing Disk helps ensure breast milk or formula mixes properly. Less air more liquid! Silicone Dome Nipple: Medium flow with Sure Flow Vents. Fashion Colors: Six to choose from. Mixing Disk: Helps ensure breast milk or formula mixes properly. Wide Mouth: Designed for easy filling and cleaning. Contoured Shape: Easy-to-hold for mom and baby. Contoured Nurser: Less air in the tummy for a happy, healthy baby. Gerber New Traditions bottles and nipples are specifically designed for both mom and baby's comfort. Each nipple has Sure Flow Vents which helps ensure a smooth, consistent flow of liquid and less air is going into your baby's tummy. 3 Nipple Choices: New Traditions makes it even easier for baby to switch between breast feeding and bottle feeding, because it has three nipple shapes. Baby can choose the nipple most like mom: Classic (traditional design); Flex (natural flexing movement); Dome (natural shape for easier latch on).